In recent years, a vehicle approach alert device is mounted on an electric vehicle (EV) or a hybrid vehicle (HV) to generate false drive sound, such that a pedestrian can easily notice an approach of the vehicle.
The vehicle approach alert device emits an approach report sound such as false drive sound through a speaker, and a sound pressure of the sound output from the speaker is set in consideration of both of the report property and the noise property. A resistance of a voice coil of the speaker changes according to the temperature of the speaker. As a result, the sound pressure output from the speaker changes. WO 2014/184829 A1 describes that a temperature of a speaker is detected by a temperature sensor attached to near or inside of the speaker, and that a sound pressure output from the speaker is corrected in consideration of the change in the resistance of a voice coil.